Two kinds of system tables exist in the database:
System tables provided by your DBMS (for more information, see your DBMS documentation)
PowerBuilder extended attribute system tables
PowerBuilder stores extended attribute information you provide when you create or modify a table (such as the text to use for labels and headings for the columns, validation rules, display formats, and edit styles) in system tables. These system tables contain information about database tables and columns. Extended attribute information extends database definitions.
In the Employee table, for example, one
column name is Emp_lname. A label and
a heading for the column are defined for PowerBuilder to use in DataWindow objects.
The column label is defined as Last Name:.
The column heading is defined as Last Name.
The label and heading are stored in the PBCatCol table
in the extended attribute system tables.
The extended attribute system tables are maintained by PowerBuilder, and only PowerBuilder users can enter information into them. Table 16-6 lists the extended attribute system tables. For more information, see Appendix A, “The Extended Attribute System Tables.”
This system table |
Stores this extended attribute information |
|---|---|
PBCatCol |
Column data such as name, header and label for reports and DataWindow objects, and header and label positions |
PBCatEdt |
Edit style names and definitions |
PBCatFmt |
Display format names and definitions |
PBCatTbl |
Table data such as name, fonts, and comments |
PBCatVld |
Validation rule names and definitions |
You can open system tables like other tables, in the Database painter.
By default, PowerBuilder shows only user-created tables in the Objects view. If you highlight Tables and select Show System Tables from the pop-up menu, PowerBuilder also displays system tables.
